Thread: pgsql: Use an indexscan not a heapscan to search pg_index in

Log Message:
-----------
Use an indexscan not a heapscan to search pg_index in get_pkey_attnames.
Noted while looking for heapscans that might need to start from block
zero.

Modified Files:
--------------
    pgsql/contrib/dblink:
        dblink.c (r1.68 -> r1.69)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/contrib/dblink/dblink.c?r1=1.68&r2=1.69)